In recent experiments we have stimulated cytolytic T lymphocytes (CTL) against Sendai virus infected cells in vitro using isolated Sendai HN protein as antigen. This antigen can be added to the in vitro stimulation culture either in free form or after being coupled covalently to agarose beads. The HA of influenza virus can also induce anti-influenza and anti-Sendai CTL. We propose to test fragments of both the Sendai HN and the influenza HA proteins to see if they will either stimulate or inhibit the stimulation of anti-viral CTL. These fragments will be tested either in free form or attached to carrier particles like the agarose beads we have already used successfully. We propose to determine the fate of the isolated viral antigen attached to beads by tracing radiolabeled antigen. We will determine the cell types that must be exposed to the bead bound antigen for stimulation to test models of H-2 restriction in CTL lysis. We will try to bind anti-viral CTL to isolated viral proteins on agarose beads to see if CTL have receptors for the viral proteins alone. We propose to use the Sendai HN and F proteins as vehicles to transfer the influenza HA protein to the surfaces of non-infected cells in a form recognizable by anti-influenza CTL.